The modern era of communications has brought about an enormous expansion of wireline and wireless networks. Computer networks, television networks, and telephony networks are experiencing an unprecedented technological expansion, fueled by consumer demands, while providing more flexibility and immediacy for information transfer.
Current and future networking technologies continue to facilitate ease of information transfer and convenience, telecommunication industry service providers are developing improvements to existing networks. For example, the evolved universal mobile telecommunications system (UMTS) terrestrial radio access network (E-UTRAN) is currently being developed. The E-UTRAN, which is also known as Long Term Evolution (LTE), is aimed at upgrading prior technologies by improving efficiency, lowering costs, improving services, making use of new spectrum opportunities, and providing better integration with other open standards.
One advantage of E-UTRAN which continues to be shared with other preceding telecommunication standards is the fact that users are enabled to access a network employing such standards while remaining mobile. Thus, for example, users having mobile terminals equipped to communicate in accordance with such standards may travel vast distances while maintaining communication with the network. By providing access to users while enabling user mobility, services are available to users while the users remain mobile. However, the mobility of users requires the network to provide continuity of service to the mobile users by enabling a user's mobile terminal to be handed over between different serving stations within corresponding different cells or service areas. To verify and test radio network deployment and operation, drive tests have been conducted in the past. Drive testing typically involved the use of specific measurement tools that could be driven or carried through an area to collect data for network operation verification. Thus, manual testing and verification of radio network operation has been common.
For existing and especially for newer networks (e.g. LTE and future networks), it may be desirable to reduce the need for drive testing or walk testing to reduce manual testing of networks and therefore reduce operational costs. Accordingly, studies regarding support for minimization of drive tests (MDT) are currently popular which aim to utilize commercial terminals for reporting of relevant measurement results in order to avoid separate manual testing with special test equipment and involvement of operator personnel.
Although the current invention is not limited to the context of MDT, MDT is deemed to be the closest current art. MDT feature enables UEs to perform Operations, Administration, and Maintenance (OAM) activities, such as neighborhood detection, measurements, logging and recording for OAM purposes, which includes radio resource management (RRM) and optimization purposes. There are two types of MDT. For immediate MDT, measurements are performed by the UEs in CONNECTED state for E-UTRA and for Cell_DCH state in UTRA. The collected information is either measured directly in the network or measured in the UE and reported to the network immediately as it becomes available. For logged MDT, measurements are performed and logged by the UEs in IDLE state and in Cell_PCH and URA_PCH state for UTRA. The UEs may report the collected and logged information to the network at a later point of time.
The UE collected measurement information (also referred to as event information) during MDT, in general, may contain location information of the user, or may contain data from which location of the user can be estimated. For example, RAN logs of immediate MDT, logs of logged MDT, and logs of problem events such as Radio Link Failure, may all contain location information or data from which location can be estimated. Acquisition of location information does not come without a burden. Location acquisition methods may consume UE power to operate UE location acquisition circuitry or to perform additional communications to determine location information. Nevertheless, the location information related to a MDT event information is often highly valuable. For example, the ability to determine that many radio link failures are occurring in a small area of a network cell can allow localized corrective actions that allow quality of service in the small area to be improved. MDT thus creates a need for an efficient and active location acquisition control scheme governing if and how location information related to MDT measurements is acquired in various networks. In the current art, such a location acquisition control scheme does not exist. In current art, MDT control and location acquisition control features are independent, and in particular for LTE, where location control and MDT control is performed by different network nodes, eNB vs. e-SMLC, the current signaling and control support is insufficient. Furthermore, in the present document the term active location is used meaning location actively performed for the specific purpose of MDT regardless of resource consumption impact, e.g. UE power and battery consumption. The resource consumption and UE battery impact of active location is comparable to positioning hardware being turned on for the purpose of MDT. The alternative to active location is best effort or passive location, where MDT only uses location information anyway available for other purpose, which is covered by prior art. While best effort location has the benefit of low resource consumption, it comes with the drawback of delivering location information not often enough for efficient MDT.
It is the objective of the current invention to address the shortcomings in current art. It is desirable to provide a solution that fulfills the new system requirements related to managing access to event information, such as MDT measurement and Radio Link Failure, with maximum simplicity and minimum impact to the current system.